Cyber Posture

CVE-2026-20874

High

Published: 13 January 2026

Published
13 January 2026
Modified
15 January 2026
KEV Added
Patch
CVSS Score 7.8 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0003 7.1th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-20874 is a high-severity Race Condition (CWE-362) vulnerability in Microsoft Windows 10 1809. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 7.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SC-4 (Information in Shared System Resources) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploitation for Privilege Escalation (T1068). What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly prevents unauthorized and unintended information transfer via shared system resources, which is the core mechanism of this race condition vulnerability in Windows Management Services.

prevent

Requires timely flaw remediation including patching the specific race condition vulnerability as detailed in the MSRC advisory.

prevent

Enforces least privilege to limit the scope and potential impact of local privilege escalation from low-privileged authorized accounts.

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
Why these techniques?

Local race condition in Windows Management Services directly enables local privilege escalation by an authorized low-privileged attacker (T1068).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Management Services allows an authorized attacker to elevate privileges locally.

Deeper analysisAI

CVE-2026-20874 is a race condition vulnerability (CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')) in Windows Management Services, also associated with CWE-416. Published on January 13, 2026, it enables an authorized attacker to elevate privileges locally. The vulnerability carries a CVSS v3.1 base score of 7.8 (AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H), indicating high impact with local attack vector, high attack complexity, low privileges required, no user interaction, and changed scope.

A local attacker with low-level authorized access (PR:L) can exploit this race condition through concurrent execution on a shared resource lacking proper synchronization. Exploitation requires physical or logical local access (AV:L) and high complexity (AC:H), but proceeds without user interaction (UI:N). Successful attacks result in privilege escalation, yielding high confidentiality, integrity, and availability impacts (C:H/I:H/A:H) within a changed scope (S:C).

The Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20874 provides details on affected versions, patches, and mitigation guidance for this vulnerability.

Details

CWE(s)

Affected Products

microsoft
windows 10 1809
≤ 10.0.17763.8276 · ≤ 10.0.17763.8276
microsoft
windows 10 21h2
≤ 10.0.19044.6809
microsoft
windows 10 22h2
≤ 10.0.19045.6809
microsoft
windows 11 23h2
≤ 10.0.22631.6491
microsoft
windows 11 24h2
≤ 10.0.26100.7623
microsoft
windows 11 25h2
≤ 10.0.26200.7623
microsoft
windows server 2019
≤ 10.0.17763.8276
microsoft
windows server 2022
≤ 10.0.20348.4648
microsoft
windows server 2022 23h2
≤ 10.0.25398.2092
microsoft
windows server 2025
≤ 10.0.26100.32230

CVEs Like This One

CVE-2026-20858Same product: Microsoft Windows 10 1809
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CVE-2026-20873Same product: Microsoft Windows 10 1809
CVE-2026-20877Same product: Microsoft Windows 10 1809
CVE-2026-32163Same product: Microsoft Windows 10 1809
CVE-2026-27927Same product: Microsoft Windows 10 1809
CVE-2026-32165Same product: Microsoft Windows 10 1809
CVE-2026-32158Same product: Microsoft Windows 10 1809
CVE-2026-32159Same product: Microsoft Windows 10 1809

References